Pneumatic hammer



Jan. 30, 1923. 1,443,532

PNEUMATIC MMER. FILED JULY 19. I920.

Patented Jan. 3Q, l li.

k1 is. $13

earner IPNEUMAIIC HAl/IMEB. o

Application filed July 19, 1920. Serial No. 397,156.

i 0 all w/lom it may concern Be it known that I, 'lrrozms L. GRAY, citizen of the United States. residing at Alameda, in the county of Alameda. and State of California, have invented certain new and useful Improvements in Pneumatie Hammers, of which the following is a specification.

This invention relates to improvements in riveting hammers and more particularly to the head construction therefor.

An important object of this invention is to provide a pneumatic riveting hammer having a head provided with novel means for heading a drift bolt as the same is be lug driven home.

Particularly, the invention forming the subject matter of this application aims to provide novel means, whereby orift bolts may be headed while being driven into wooden structures, wood bridges, and the like.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this application and in which like numerals are employed to designate like parts throughout the same:

Figure l is a fragmentary view of the riveting hammer in use, parts thereof being shown in section,

Figure 2 is an end elevation of the head of the hammer,

Figure 3 is a fragmentary perspective view of the head of the hammer.

In the drawing, wherein for the purpose of illustration is shown a preferred embodiment of the invention, the numerals l0 and 11 designate planks or large pieces of timber which are to be connected by means of drift bolts 12. It might be added that the planks or beams 10 and 11 may be used in connection with the building of various wooden structures such as wood vessels, frame buildings. bridges, and so forth, and the drift bolts may be several feet or more in length and possessed of the requisite thickness.

The invention forming the subject matter of this application is used in a pneumatic hammer is having a barrel 16 within which a plunger reciprocates for imparting a driving movement to the hammer head 18. The pneumatic hammer may be of any desired construction so that a detailed illustration of the swell being less than half the depth of the recess 20.

In the practice of the invention, the pneumatic hammer 14 is arranged in longitudinal alinement with the drift bolt 12 and when brought into operation will cause the drift bolt to enter the planks or beams 10 and 11. However, as the bolt is being driven home, the convex swell 22 of the head will displace the metal in the center of the drift bolt and thereby start to form the head 24. As the heading of the bolt takes place while the bolt is being driven home, the pneumatic hammer serves a double function. namely that of driving the bolt and heading the same. Upon being driven home the head 2% of the bolt seats within a recess or counter-sunk portion 26 in a clincher ring-28.

My hammer head is intended particularly for use in riveting wooden timbers in which a rod of cold iron is forced into an auger hole of slightly less diameter than the rod. In forcing such rod home, head is formed on the rod under the blows of the hammer. A practical mechanic, driving a rod or iron into a wooden structure and using a machinists hand hammer, would first strike the rod with the round end of the hammer to start the formation of the head and would finish by using the flat side of the hammer.

In ordinarily forming the head on a rivet or bolt, it is necessary to strike the end portion of the same with the riveting hammer with the result that a considerable strain is placed on the operator and also on the tool. This excessive strain placed upon the tool as the result of disposing the same angularly with relation to the bolt greatly weakens the parts and frequently causes the same to break. It will be noted, however, that in the use of this invention, the pneumatic hammer is placed in longitudinal alinement with the bolt and thereby eliminates the strain which is ordinarily placed upon a riveting hammer when in use.

In the use of my tool, the end of the rod lOO is upset and a head formed, as shown in Fig. 1. If, after the head is sufiiciently formed, the old style hammer head he used to finish the work, 2L button-shaped head will be produced.

In the use of the invention it has been found that work progresses much more rapidly since the necessity of separately heading the bolts is entirely dispensed with.

It is to be understood that the form of the invention herewith shown and described is to be taken as it preferred embodiment of the same and that such minor changes in arrangement and construction of parts may be made as will fall within the spirit of 1.5 the invention and the scope of what is claimed.

Having thus described the invention, what is claimed as new is:

A hammer heed having its forward por-20 tion provided with a drift-bolt-receiving recess. said recess being provided with a centrally arranged convex swell of less height than half the depth of said recess.

In testimony whereof I afiix my signs 25 ture.

THOMAS L. GRAY. 

